This example specifies the system-generated method zip in its RETURN statement.
First you must create the structured UDT address.
CREATE TYPE address AS (street VARCHAR(20), zip CHARACTER(5)) NOT FINAL;
Now you can create the SQL UDF zipcode, which specifies the system-generated method zip in its RETURN statement.
CREATE FUNCTION test.zipcode (a address) RETURNS CHARACTER(5) LANGUAGE SQL DETERMINISTIC CONTAINS SQL SPECIFIC test.zipcode CALLED ON NULL INPUT SQL SECURITY DEFINER COLLATION INVOKER INLINE TYPE 1 RETURN a.zip();